System and method for removal of water from oil

ABSTRACT

A system and method for removing water from oil comprises: a housing, an oil inlet tube fluidly connecting the oil supply and an oil inlet of the housing, an inlet pump configured to pump a flow of oil from the oil supply to the oil inlet at a first pumping flow rate, an oil outlet tube fluidly connecting an oil outlet of the housing and the oil supply, an outlet pump adapted to pump a flow of oil from the oil outlet to the oil supply at a second pumping flow rate, an air inlet tube providing a gas connection between a air supply unit and an air inlet of the housing, and an air outlet tube providing a gas connection between an air outlet of the housing and the air supply unit, wherein the second pumping flow rate is greater than the first pumping flow rate

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage application pursuant to 35 U.S.C. §371 of International Application No. PCT/DK2019/050384 filed on Dec. 11,2019, which claims priority to, and the benefit of, Denmark PatentApplication No. PA201870812 filed on. Dec. 12, 2018. The entire contentsof such applications are hereby incorporated by reference.

The present invention relates to a system for removing water from oilfrom an oil supply, where the system comprises a housing comprising aninner opening, an oil inlet tube connecting the oil supply and an oilinlet of the housing, where the oil inlet tube comprises an inlet pumpadapted to provide a flow of oil in a direction from said oil supply tosaid oil inlet, an oil outlet tube connecting an oil outlet of thehousing and the oil supply, where the oil outlet tube comprises anoutlet pump adapted to provide a flow of oil in a direction from saidoil outlet to said oil supply, an air inlet tube providing a gasconnection between an air supply unit and an air inlet of the housing,and an air outlet tube providing a gas connection between an air outletof the housing and the air supply unit, where said outlet pump isadapted to provide a flow at a higher pumping flow rate than the pumpingflow rate provided by said inlet pump.

The present invention further relates to a method of removing water fromoil from an oil supply.

Oil is used as a lubricant and cooling agent in a vast number ofdifferent types of machinery and engines. During operation of themachinery or engine, the oil is slowly contaminated inter alia withsolid particles arising from wear of the machinery and with water whichmay have been introduced into the oil through leaks in the joints of thetubing and machinery.

It is important to keep the oil as clean as possible not only fromparticles, but also from water. Water will not only change the viscosityof the oil thereby leading to a change of the ability of the oil to beused as a lubrication, but may also facilitate the existence ofmicroorganisms which will degrade the oil, complicate filtering the oiland lead to formation of rust. All of these factors will lead to anincreased degradation of the oil and therefore to a reduced lifetime ofboth the oil and of the elements of the machinery or engine. Therefore,it is important to remove water from the oil.

It is known to remove water from the oil by one of a number of differenttechniques, such as by:

-   -   heating the oil,    -   centrifuging the oil,    -   exposing the oil to a water-absorbing material,    -   filtering the oil in a vacuum chamber, or    -   settling.

However, common to these techniques are that they either require a lotof space or can be quite expensive.

Thus, in situations where both the available space for manoeuvring andmounting a water removal system into place is very limited, such asaboard ships, and where the user is very cost-sensitive, there is a needfor a water removal system that provides a compact and simple solution.

In accordance with the invention, there is provided a system forremoving water from oil from an oil supply, where the system comprises ahousing comprising an inner opening, an oil inlet tube connecting theoil supply and an oil inlet of the housing, where the oil inlet tubecomprises an inlet pump adapted to provide a flow of oil in a directionfrom said oil supply to said oil inlet, an oil outlet tube connecting anoil outlet of the housing and the oil supply, where the oil outlet tubecomprises an outlet pump adapted to provide a flow of oil in a directionfrom said oil outlet to said oil supply, an air inlet tube providing agas connection between an air supply unit and an air inlet of thehousing, and an air outlet tube providing a gas connection between anair outlet of the housing and the air supply unit, where said outletpump is adapted to provide a flow at a higher pumping flow rate than thepumping flow rate provided by said inlet pump.

By providing a system which has a housing in which both oil and air areintroduced, it is possible to make use of the chemical separationprocess, stripping, which is also referred to as desorption for removingthe water from the oil. In the desorption process, one component of aliquid stream, i.e. water, moves by mass transfer into a vapour phase,i.e. steam, through the liquid-vapour interface. Desorption is aneffective and simple (and thereby a low-cost) way of removing water fromoil.

By providing both an inlet pump and an outlet pump for leading the flowof oil through the housing, it is ensured that the flow of oil can becontrolled according to required needs, such as the amount of oil in theoil supply and the amount of water in the oil, e.g. where the flow ofoil through the system is lowered if the amount of water in the oilincreases.

When using a system for removing water from oil by way of desorption,the oil and the air is combined. This combination may result information of foam (a mass of small air bubbles) on the surface of theoil. If not minimised, the foam may potentially spread to the otherelements of the system, such as to the outlet pump, the air tubing orair supply unit, which may lead to these elements being damaged or atbest having to be cleaned to function properly again.

Thus, it is an advantage that said outlet pump is adapted to provide aflow at a higher pumping flow rate than the pumping flow rate providedby said inlet pump. Thereby, it is ensured that foam and oil are removedfrom said housing at a higher pumping flow rate than the oil isintroduced, which means that any foam created will be removed as quicklyas it is formed. The risk of other elements of the system being damagedby the oil and foam is thereby eliminated.

Further, it is ensured that the oil is removed from said housingimmediately after reaching the oil outlet of said housing so that thereis no risk of the oil overflowing said housing. The manufacturing ofsaid system is also made more simple as e.g. sensors for detecting ifoil is overflowing said housing may be spared.

Thus, a simple and safe system is provided, where the requirement forunwanted service due to oil contamination is eliminated.

In an embodiment, a first part of the inner opening of said housing canbe arranged downstream of said oil inlet and upstream of said oiloutlet.

By providing that a first part of said inner opening is arrangeddownstream of said oil inlet and upstream of said oil outlet, it isensured that the oil is only present in a part/section of said inneropening and therefore does not fill up said inner opening completely,but only partly.

The result is that a volume/part/section of said inner opening is notfilled with oil (e.g. a second part) which has the advantage that oil orfoam accidentally bypassing the oil outlet does not have immediateaccess to the other elements of the system, but instead stays in thehousing until being removed via the oil outlet.

Further, the air in the housing may be accumulated in thevolume/part/section of said inner opening not filled with oil beforebeing removed via said air outlet of said housing, whereby oilaccidentally being led past the oil outlet by the air will drop back toa position prior to said oil outlet instead of escaping the housing e.g.via the air outlet.

In an embodiment, said oil outlet can be arranged at a vertically higherlocation than said oil inlet.

By a vertically higher location is understood relative to gravity, whenthe system is placed, as it will be during operation. Hence, thevertically higher location is gravitationally higher, such that an itemsubjected to no other forces would fall from the plane of the higherposition towards the plane of the lower position.

Thereby, the oil can enter said housing via the oil inlet and fill theinner opening until the surface of the oil reaches the oil outlet, wherethe oil leaves the inner opening. Therefore, the system functions bymeans of an overflow of oil.

Thus, in an embodiment, the oil can exit the housing by means of anoverflow of oil, and the housing can therefore be an overflow system.

In an embodiment, the invention teaches a system for removing water fromoil from an oil supply, where the system comprises

-   -   a housing comprising an inner opening,    -   an oil inlet tube connecting the oil supply and an oil inlet of        the housing, where the oil inlet tube comprises an inlet pump        adapted to provide a flow of oil in a direction from said oil        supply to said oil inlet,    -   an oil outlet tube connecting an oil outlet of the housing and        the oil supply, where the oil outlet tube comprises an outlet        pump adapted to provide a flow of oil in a direction from said        oil outlet to said oil supply,    -   an air inlet tube providing a gas connection between an air        supply unit and an air inlet of the housing, and    -   an air outlet tube providing a gas connection between an air        outlet of the housing and the air supply unit,    -   characterised in that    -   said outlet pump is adapted to provide a flow at a higher        pumping flow rate than the pumping flow rate provided by said        inlet pump, and in that    -   said oil outlet is arranged at a vertically higher location than        said oil inlet.

Providing an overflow system combined with the outlet pump operating ata higher pumping flow rate than the inlet pump results in that theamount of oil can be kept constant inside the housing. This ensures, inan effective and simple way, that the oil is kept in the housing for arequired time-interval sufficient for removing water, without e.g.risking that the oil is oxidated or that the oil is kept in the housingeven though the water has been removed.

The overflow system enabled by the position of the oil outlet verticallyhigher than the oil inlet thus works together with the inlet and outletpump to avoid adverse effects of the formation of foam inside thechamber.

Foam tends to take up a large volume, as it comprises a significantamount of gas relative to the liquid forming the shell of the bubbles.Hence, the foam will make the level of the fluid contents within thechamber rise, when foam is formed within the chamber. This increase inthe fluid level will cause the fluid to reach the outlet, thus a quickerrise of the fluid level, e.g. cause by the formation of foam, will leadto fluid leaving the chamber sooner, as the level of fluid within thechamber reaches the oil outlet.

This effect is supported by the outlet pump being adapted to provide aflow at a higher pumping flow rate than the pumping flow rate providedby said inlet pump. This ensures that the foam, having a low density,will be driven or sucked through the outlet as soon as it is formed. Asthe foam is lighter than the oil, it will form on the top surface of theliquid oil level and will reach the oil outlet before the liquid oil,which has not formed foam, and hence it will feel the pull of the outletbefore the liquid oil, as the foam comes within range first. This effectis also enhanced by the lower density of the foam compared to the liquidoil, as a smaller force is necessary to move the foam than the liquidoil. This benefit of the foam being efficiently removed is achievedbecause the oil outlet is at a vertically, i.e. gravitationally, higherposition of the chamber than the oil inlet, as that ensures that thelight foam reaches the oil outlet before the liquid oil. If the oiloutlet was gravitationally below the oil inlet, the foam would stillform on top of the liquid level, but the heavier liquid oil would bepulled from the chamber first, and the foam might continue to rise ontop of the liquid oil level.

Hence, the combination of the outlet pump being adapted to provide aflow at a higher pumping flow rate than the pumping flow rate providedby the inlet pump and the oil outlet being arranged at a verticallyhigher location than said oil inlet ensures that any foam forming on topof the liquid oil level is removed efficiently, and it allows control ofthe fluid level within the chamber.

In an embodiment, the system can further comprise a heating elementarranged upstream of said oil outlet.

Preferably, the oil contacts (flows past) said heating element on itsway towards the oil outlet of the housing. The heating element may havea higher temperature than the oil flowing past it so that the heatingelement is heating the oil. The heating element can be set to anyrequired power so that the oil is heated to a desired temperature, wherethe required power depends on the temperature of the oil, when it entersthe system. Therefore, the system may further comprise a temperaturesensor for detecting the temperature of the oil which temperature sensorcan be used for operating the heating element.

Heating the oil has the advantage that the air entering said housing isalso heated. This is important as the amount of water removed by the airis dependent on the temperature and humidity of the air—the higher thetemperature, the higher the amount of water which can be removed.

The amount of water, which can be removed by the air, is illustrated bythe well-known Molliers diagram. There, it is seen that the amount ofwater, which can be present in the air, before saturation is reached,increases with an increase in the temperature of the air.

Thus, by providing a heating element, the temperature of the oil and airpresent in the housing can be increased, and the amount of water removedfrom the oil can be increased.

In an embodiment, the air inlet of the housing can be arrangeddownstream of said oil inlet.

The air inlet of the housing can therefore be arranged at said firstpart of said inner opening.

Thereby, it is ensured that the air is mixed with the oil. This mixingresults in that the air may be heated by the oil (if the oil temperatureis higher than the air temperature) and that the air may move (asbubbles) through the oil, which increases the ability of the air toremove the water from the oil.

In an embodiment, the housing can further comprise a porous materialarranged in said first part of said inner opening.

The porous material may be arranged so that it covers or almostcompletely covers a cross-section of the housing. The porosity of thematerial should be of a size so that the oil can flow through itrelatively easy without experiencing a large pressure drop.

In an embodiment, said porous material can be arranged at least partlydownstream of said air inlet.

Thereby, both the oil and the air have to flow through the porousmaterial before reaching the oil outlet and the air outlet,respectively.

When the air flows through the porous material it has to spread outacross the porous material to flow through the pores of said material.The advantage is that the air is then prevented from accumulating intolarge air bubbles, but instead is distributed out into several small airbubbles. This increases the total surface area of the air and thereforeincreases the amount of water able to be collected by the air on its waythrough the oil.

In an embodiment, said air outlet can be arranged at a second part ofthe inner opening of said housing, said second part can be arrangedvertically above said oil outlet.

It is an advantage to also have a second part in the inner opening ofthe housing, with said second part being arranged vertically above saidoil inlet. Thereby, the air, which has flown through the oil, mayaccumulate at said second part which is free of any oil as the oilleaves the housing via the oil outlet. Also, as written above, air maybe accumulated in said second part before being removed via said airoutlet, whereby oil accidentally being led past the oil outlet by theair can drop/fall back to a position prior to said oil outlet instead ofescaping the housing via the air outlet.

In an embodiment, said system can further comprise an oil filterarranged in the oil outlet tube.

Providing an oil filter in the oil outlet tube has the advantage thatthe oil is filtered before returning to the oil supply. This is known tobe an advantage as this way, e.g. particle contaminants are removed fromthe oil which would otherwise reduce the lifetime of themachinery/equipment using the oil in the oil supply.

Arranging the oil filter downstream of the housing has the advantagethat the oil filter is not exposed to the water present in the oil.Water is known to influence the filtering efficiency of an oil filterand is therefore an unwanted element in the oil.

In an embodiment, said oil filter can be arranged downstream of theoutlet pump.

Thereby, the pressure of oil provided to the oil filter can be keptrelatively constant so that the structure of the oil filter is notstressed unnecessarily, e.g. by a fluctuating pressure.

In an embodiment, said system can further comprise an air vent tubewhich connects the oil filter and the housing.

As the pumping flow rate of the outlet pump is higher than that of theinlet pump, the outlet pump may run dry at times and may pump not onlyoil, but also air from the housing. For this reason, air will also beled to the oil filter.

It is known when having air present in the oil that the pressure dropacross the filter will cause the air bubbles in the oil to expand into alarger volume and may also lead to a release of dissolved air. Thisexpansion of air will pull solid particles to be filtered through thepores or openings of the oil filter and release already trapped solidcontaminants, thereby leading to a decreased filtering efficiency.

Pressurising the filtered oil at the outlet of the oil filter, i.e.providing a back pressure, ensures that all air remains dissolved in theoil. Thus, no free air bubbles are formed when the oil passes throughthe filter. For this reason, a back pressure (such as a valve) may bearranged at the outlet side of the oil filter.

However, said system may also or alternatively comprise an air vent tubewhich connects the oil filter with the housing of the system. By havingsuch an air vent tube, at least the main part of the air beingintroduced to the oil filter may be led back to said housing via the airvent tube and be reused or released via the air outlet tube instead ofbeing led through the oil filter and to the oil supply.

In an embodiment, the air inlet tube can comprise an air vent/fan. Anair vent/fan is a low-cost and effective means of providing a flow ofair.

In an embodiment, the air supply unit can comprise a condensing system.The condensing system may comprise a fan-cooled radiator, which is alow-cost, simple and effective means of removing a water content fromair by condensation.

In accordance with the invention, there is further provided a method ofremoving water from oil from an oil supply, where the method comprisesthe steps of providing a housing comprising an inner opening,introducing the oil from the oil supply via an oil inlet tube to thehousing, where the oil inlet tube comprises an inlet pump providing aflow of oil in a direction from said oil supply to said oil inlet,releasing the oil from the housing via an oil outlet to an oil outlettube leading to said oil supply, where the oil outlet tube comprises anoutlet pump providing a flow of oil in a direction from said oil outletto said oil supply, introducing a flow of air from an air supply unitinto the housing, via an air inlet tube, and removing a flow of air fromthe housing via an air outlet tube, where said outlet pump is providinga flow at a higher pumping flow rate than the pumping flow rate providedby said inlet pump.

The structure and function of the system and the method of using it willbe described in more detail below with references to exemplaryembodiments shown in the drawings wherein,

FIG. 1 shows an embodiment of a system according to the invention.

FIG. 2 shows an embodiment of a system according to the invention.

In FIG. 1 , a system 1 for removing water from oil from an oil supply(not shown) is shown.

The system 1 is shown to have an oil inlet tube 2 and an oil outlet tube3.

The oil inlet tube 2 connects the oil supply at a first end 2 a and anoil inlet 4 of a housing 5 at a second end 2 b. The oil inlet tube 2 isled through an inlet pump 6 which is adapted to provide a flow of oil ina direction from said oil supply to said oil inlet 4 as indicated by thearrow 2′.

It is shown that the oil inlet tube 2 may further be led through anon-return valve 7 for preventing oil returning to the oil supply viathe oil inlet tube 2 (i.e. counter to the direction of the arrow 2′).The non-return valve 7 may be set at e.g. 4 bars to prevent oil from theoil supply from entering the system at standstill. The non-return valve7 may be arranged downstream of the inlet pump 6.

The oil inlet tube 2 may further be led through a heating element 8 forheating the oil before it enters the housing 5 (e.g. to 50° C.-80° C.).However, it is foreseen that the heating element 8 may be arranged inthe housing 5 instead, as long as it heats the oil before the oil istreated in the housing 5. The heating element 8 may e.g. provide 1000Wand include a temperature control to ensure that the oil is heatedcorrectly according to the specific temperature of the oil so that therequired oil temperature of the oil in the housing 5 is reached. Theheating element 8 may be arranged downstream of the inlet pump 6 and/orof the non-return valve 7.

At a first end 10, the oil outlet tube 3 connects an oil outlet 9 of thehousing 5 to said oil supply at a second end 11. The oil outlet tube 3is led through an outlet pump 12 which is adapted to provide a flow ofoil in a direction from said oil outlet 9 to said oil supply asindicated by the arrow 3′.

Said outlet pump 12 is adapted to provide a flow at a higher pumpingflow rate than the pumping flow rate provided by said inlet pump 6. Inone embodiment, the pumping flow rate of the outlet pump 12 may be morethan 10% higher than the pumping flow rate of the inlet pump 6. In oneembodiment, the pumping flow rate of the outlet pump 12 may be more than50% higher than the pumping flow rate of the inlet pump 6.

The oil outlet tube 3 may further be led through an oil filter 13 and asecond non-return valve 14, both of which may be arranged downstream ofthe outlet pump 12.

In a preferred embodiment of the invention, the oil inlet 4 of thehousing 5 is placed at a vertically lower position than the oil outlet 9of the housing 5. By vertically lower is to be understood in relation togravity, when the system is configured, as it would be during operation.Hence, an item released at the plane of the vertically, i.e.gravitationally higher, oil outlet 9 and subjected to no other forcesthan gravity would fall towards the plane in a vertically lower positionsuch as the plane in which the oil inlet 4 is placed. In otherdimensions than the vertical direction, the oil inlet 4 and the oiloutlet 9 of the housing 5 may be placed independently of each other,such that they may be on the same side of the housing 5, on opposingsides, or at an angle compared to each other.

In a variant of the invention, the oil inlet 4 of the housing 5 isplaced in the lower half of the chamber 5. In such an embodiment, theoil outlet 9 of the housing 5 may be placed in the upper half of thechamber 5. Upper and lower is still considered relative to the directionof gravity, when the chamber 5 is in the position it will be in duringoperation of the system for removing water from oil.

Placement of the oil inlet 4 of the housing 5 above the oil outlet 9 ofthe housing 5 enables the system to operate as an overflow system,wherein the fluid exits the chamber 5 once a certain level has beenreached. The dimensions of the chamber 5 as well as the verticalposition of the oil outlet 9 of the chamber 5 may vary between differentembodiments of the system such that the volume of fluid, which may becontained within the chamber, before the oil outlet is reached by thesurface level of the fluid, is matched to the specific embodiment of thesystem.

The oil filter 13 may be arranged in a filter unit (not shown) and maycomprise (be made of) a natural or synthetic polymer, such as acellulose material. The oil filter 13 may have a cylindrical shape withan inner opening, where an outer surface of the oil filter 13 defines aninlet of the oil filter 13, so that the oil flows from the outer surfaceto the inner opening of said oil filter 13 before leaving the oil filter13 (and the filter unit).

The second non-return valve 14 may be a back pressure valve 14, so thata pressure is applied on the oil filter 13.

As explained earlier, it is known when having e.g. air present in theoil that the pressure drop across the oil filter 13 will cause airbubbles in the oil to expand into a larger volume and may also releasedissolved air into the oil. This expansion of air will pull solidparticles to be filtered through the pores or openings of the oil filter13 and release already trapped solid contaminants, thereby leading to adecreased filtering efficiency.

Pressurising the filtered oil at the outlet of the oil filter 13, i.e. aback pressure by use of the second non-return valve 14, ensures that allair in the oil flowing through the oil filter 13 remains dissolved inthe oil. Thus, no free air bubbles are formed when the oil passesthrough the oil filter 13. For this reason, a back pressure may bearranged at the outlet side of the oil filter 13.

An air vent tube 15 is shown to connect the oil filter 13 with thehousing 5. However, it is foreseen that said air vent tube 15 connects afilter unit (containing the oil filter 13 in an inner opening) with thehousing 5.

When providing that the outlet pump 12 operates at a higher pumping flowrate than the inlet pump 6, not only oil, but also an amount of air, isled to the oil filter 13 and filter unit.

As mentioned earlier, it is desired to have a minimum amount of airpresent in the oil, when it flows through the oil filter 13. For thisreason, it is an advantage that the system 1 comprises the air vent tube15 in order to remove as much air as possible from the oil+air mixturebeing pumped out from said housing 5 and in order to lead the air backto said housing 5 as shown by the arrow 15′.

Advantageously, the air vent tube 15 is connected to a vertically upperpart of the said filter unit (oil filter), as air would usuallyaccumulate at said vertically upper part.

A third non-return valve 16 may be arranged in the air vent tube 15 toallow air to leave, but not enter, the oil filter 13 (filter unit).

In FIG. 1 , it is shown that the system 1 further comprises an air inlettube 17, an air outlet tube 18 and an air supply unit 19.

The air inlet tube 17 provides a gas connection between the air supplyunit 19 and an air inlet 20 of the housing 5. An air pump 21 (fan/airvent) may be inserted in the air inlet tube 17 to provide a flow of airin a direction from said air supply unit 19 to said housing 5, as isindicated by the arrow 17′, to ensure that the required flow of air isintroduced into the housing 5.

The air outlet tube 18 provides a gas connection between an air outlet22 of the housing 5 and the air supply unit 19. Air containing anincreased amount of water (maybe even saturated air) compared to the airintroduced in said housing 5 may then leave said housing 5 and flow tosaid air supply unit 19 as is indicated by the arrow 18′.

The air supply unit 19 may comprise a condensing system 23 for removingat least part of the water content in the air. The condensing system 23may be a fan-cooled radiator, a cooling liquid condensing system orother. The water removed from the air may leave the system via a waterdrain tube 24.

FIG. 2 shows an embodiment of a system 1 according to the invention.

For similar features as the features shown in FIG. 1 , similar referencenumbers have been used.

As in FIG. 1 , the system 1 shown in FIG. 2 comprises an oil inlet tube2, an oil outlet tube 3, an air inlet tube 17 and an air outlet tube 18.However, in FIG. 2 , the oil inlet 2 and oil outlet tubes 3 are shown tobe connected to an oil supply 25.

In FIG. 2 , the housing 5 of the system 1 is shown to have an L-shapecomprising a lower surface 26, a middle surface 27 and a top horizontalsurface 28, and a first 29, second 30 and third vertical surface 31.

In an inner opening 32 of the housing 5, a heating element 8 and aporous material 33 may be arranged.

As is indicated by the arrows, the oil is introduced into the housing 5via the oil inlet 4 (lower horizontal surface 26) and is filling up theinner opening 32 of the housing 5 and passes the porous material 33,until the oil surface 36 reaches the oil outlet 9 (third verticalsurface 31). The filled part of said inner opening 32 defines a firstpart 34 of said inner opening 32 arranged downstream of said oil inlet 4and upstream of said oil outlet 9. The remainder of said inner opening32 defines a second part 35 of the inner opening 32 of said housing 5,said second part 35 being arranged vertically above said oil outlet 9.On the way from said oil inlet 4 to said oil outlet 9, the oil is heatedby the heating element 8.

Simultaneously, as indicated by the arrows, air is introduced into thehousing 5 via the air inlet 20 arranged in said first part 34 downstreamof said oil inlet 4 and upstream of said oil outlet 9 (middle horizontalsurface 27). The air mixes with the oil and is divided into severalsmall air bubbles when passing the porous material 33. During themixing, the air is heated by the heated oil and absorbs water from theoil before leaving the housing 5 via the air outlet 22 arranged at thesecond part 35 of said inner opening 32, said second part 35 beingarranged vertically above said oil outlet 9 (top horizontal surface 28).

The invention claimed is:
 1. A method of removing water from an oil ofan oil supply, wherein the method comprises: providing a housing thatdefines an inner space; enabling an oil to flow from an oil supplythrough an oil inlet tube to an oil inlet of the housing; fluidlycoupling an inlet pump to the oil inlet tube so as to provide a firstflow of oil from the oil supply to the oil inlet according to a firstpumping flow rate; introducing a flow of a gas through a gas inlet tubeand into the inner space of the housing; after a surface level of theoil rises at least to an oil outlet position, releasing to an oiloutlet, the oil and a foam formed on a surface of the oil so that thereleased oil and foam flow to an oil outlet tube that is fluidlyconnected to the oil supply; fluidly coupling an outlet pump to the oiloutlet tube so as to provide a second flow of the oil from the oiloutlet to the oil supply according to a second pumping flow rate,wherein the second pumping flow rate is greater than the first pumpingflow rate; and removing a portion of the gas from the inner space of thehousing through a gas outlet tube, thereby removing water from the oil.2. The method of claim 1, further comprising: heating a portion of theoil in the inner space of the housing; and condensing water from theflow of the gas before the step of introducing the flow of gas throughthe gas inlet tube and into the inner space of the housing.
 3. Themethod of claim 1, wherein the housing is configured so that: part ofthe inner space of the housing is positioned downstream of the oil inletand upstream of the oil outlet; and the gas inlet of the housing ispositioned downstream of the oil inlet.
 4. The method of claim 1,wherein the housing is configured so that, when the housing isvertically oriented: a first part of the inner space of the housing ispositioned downstream of the oil inlet and upstream of the oil outlet;and a second part of the inner space of the housing is positionedvertically above the oil outlet.
 5. The method of claim 4, wherein thegas inlet of the housing is positioned downstream of the oil inlet.
 6. Amethod of manufacturing a system that is operable to remove water froman oil of an oil supply, wherein the method comprises: configuring ahousing to define an inner space, wherein the configuring of the housingcomprises configuring the housing to enable an oil to flow from an oilsupply through an oil inlet tube to an oil inlet of the housing; fluidlycoupling an inlet pump to the oil inlet tube so as to enable a firstflow of the oil from the oil supply to the oil inlet according to afirst pumping flow rate, wherein: the housing is configured to receive aflow of a gas through a gas inlet tube and into the inner space of thehousing; and the housing is configured so that, after a surface level ofthe oil rises at least to a position of an oil outlet of the housing,the oil and a foam formed on a surface of the oil are released to theoil outlet and flow to an oil outlet tube that is fluidly connected tothe oil supply; and fluidly coupling an outlet pump to the oil outlettube so as to enable a second flow of the oil from the oil outlet to theoil supply according to a second pumping flow rate, wherein the secondpumping flow rate is greater than the first pumping flow rate, whereinthe housing is configured to output a portion of the gas from the innerspace of the housing through a gas outlet tube, thereby removing waterfrom the oil.
 7. The method of claim 6, further comprising: configuringa heating element to heat a portion of the oil in the inner space of thehousing; and configuring a condenser to condense water from the flow ofthe gas upstream of the gas inlet tube.
 8. The method of claim 6,wherein the configuring of the housing comprises configuring the housingso that: part of the inner space of the housing is positioned downstreamof the oil inlet and upstream of the oil outlet; and the gas inlet ofthe housing is positioned downstream of the oil inlet.
 9. The method ofclaim 6, wherein the configuring of the housing comprises configuringthe housing so that, when the system is vertically oriented: a firstpart of the inner space of the housing is positioned downstream of theoil inlet and upstream of the oil outlet; and a second part of the innerspace of the housing is positioned vertically above the oil outlet. 10.A method of facilitating a separation and removal of water from an oilof an oil supply, wherein the method comprises: configuring a housing todefine an inner space and to enable an oil to flow from an oil supplythrough an oil inlet tube to an oil inlet of the housing; configuring aninlet pump to fluidly couple to the oil inlet tube so as to enable afirst flow of the oil from the oil supply to the oil inlet according toa first pumping flow rate, wherein: the configuring of the housingcomprises configuring the housing to receive a flow of a gas through agas inlet tube and into the inner space of the housing; and theconfiguring of the housing further comprises configuring the housing sothat, after a surface level of the oil rises at least to a position ofan oil outlet of the housing, the oil and a foam formed on a surface ofthe oil are released to the oil outlet and flow to an oil outlet tubethat is fluidly connected to the oil supply; and configuring an outletpump to fluidly couple to the oil outlet tube so as to provide a secondflow of the oil from the oil outlet to the oil supply according to asecond pumping flow rate, wherein the second pumping flow rate isgreater than the first pumping flow rate, wherein the configuring of thehousing further comprises configuring the housing to output a portion ofthe gas from the inner space of the housing through a gas outlet tube,thereby removing water from the oil.
 11. The method of claim 10, furthercomprising configuring a heating element to heat a portion of the oil inthe inner space of the housing.
 12. The method of claim 11, furthercomprising configuring a condenser to condense water from the flow ofthe gas upstream of the gas inlet tube.
 13. The method of claim 12,further comprising positioning a porous material in the inner space ofthe housing at least partly downstream of the gas inlet tube, so thatthe porous material distributes the flow of gas into bubbles in the oil.14. The method of claim 10, wherein the configuring of the housingfurther comprises configuring the housing so that, when the housing isvertically oriented: a first part of the inner space of the housing ispositioned downstream of the oil inlet and upstream of the oil outlet;and a second part of the inner space of the housing is positionedvertically above the oil outlet.
 15. The method of claim 14, furthercomprising configuring a water drain tube downstream from the gas outlettube.
 16. The method of claim 10, wherein the configuring of the housingfurther comprises configuring a water drain tube downstream from the gasoutlet tube.